The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Hydraulic transducers, that is, devices that are powered by pressurized hydraulic fluid and convert such energy to linear translation and force are common components of many power transmission and control devices. Hydraulic actuators or operators, as they are commonly called, find wide application of motor vehicle automatic transmissions and dual clutch transmissions (DCT's). The operability and service life of such actuators is related almost exclusively to the integrity of the elastomeric seal disposed between the translating component, the piston, and the stationary component, the housing. If the seal is defective, either upon assembly or later becomes so, the actuator will, at a minimum, leak and thus require more time to operate, may not be capable of achieving full design force and waste pressurized hydraulic fluid which could adversely impact operation of other components or the entire transmission. In a worst case scenario, the leak is so severe that the actuator simply does not respond to pressure inputs and fails to properly translate the associated, clutch, brake, shift fork or other component.
Viewed from a chronological perspective rather than from the degree of failure, it is one type of difficulty to have the seal fail after years of service and tens of thousands of miles of travel and another to have the seal fail essentially upon installation because of a manufacturing defect. It is therefore apparent that by inspecting each piston seal the latter type of failure can be virtually eliminated. The present invention is thus directed to a method and apparatus of inspecting piston seals, detecting flaws in such seals and accepting flawless piston seals and rejecting flawed piston seals.